Many researches have been conducted regarding the stability of boats, and the most important thing in arranging many parts in boats is ensuring the stability of hulls.
All designs of boats focus on ensuring stability in the forward and backward directions (pitch) and stability in the horizontal direction (rolling), which are the important factors in the stability, and the most important factor in the rolling stability is a shape of a floating body such as a hull.
In general, the morphological stability of a boat is influenced most by the center of gravity and the center of buoyancy. To ensure such stability, boats are divided into a monohull, a catamaran, and a trimaran according to the shapes of their hulls.
From among various kinds of boats classified according to morphological characteristics as described above, the trimaran has many floating bodies in the hull and thus is easiest to ensure stability and has stability.
The trimaran has high stability, but occupies more spaces than the other boats due to an extension floating body extended in a lengthwise direction when it is anchored at a dock, and thus has many problems in use.
To solve the disadvantage of the trimarans, trimarans have been developed to have outer hulls which are installed at the left and right sides and can be expanded and contracted arbitrarily, and to maximize efficiency of space utilization.
As a related-art trimaran, Korean Patent Publication No. 10-2013-0046674 discloses “Trimaran Boat With the Extension Foldable Buoyance.” This related-art trimaran can have its left and right extension floating bodies folded when it is docked at a harbor, and thus occupies less spaces, and also, can have the left and right expansion floating bodies expanded when it sails, and thus has an advantage of minimizing rolling.
However, the above-described related-art trimaran has not overcome disadvantages caused by the large overall width thereof, that is, poor performance in navigating and turning to change a direction when it sails, and a high possibility that the boat is overturned when it quickly turns since an auxiliary hull at one side floats off from a water surface.
Therefore, there is a demand for a technique for a trimaran for enhancing navigation performance and turning performance when its direction is changed, and increasing stability when it quickly turns, such that many people can easily and safely use the trimaran.
Meanwhile, various kinds of boats including trimarans, which can use wind power and solar power as driving power as oil which is a fossil fuel has run out, have been developed and distributed.
As related-art technology described above, Korean Patent Registration No. 10-1279744 discloses “Multi-functional Boat Using Solar and Wind Energy,” and relates to a multi-functional boat using solar and wind power energy, which includes a manual driving unit and an automatic driving unit.
However, the related-art technology may produce power using a blade or drive by directly driving propellers, or may use power by charging a battery, and also, uses a solar cell panel as an auxiliary element. Therefore, it is greatly doubted whether the boat of this configuration can sail in the ocean without any assistance of an auxiliary power source.
In addition, Korean Patent Publication No. 10-2013-94077 discloses “Hybrid Boat Using Wind Power and Solar Energy as Driving Power.” This invention is characterized of attaching a power generation solar cell plate to a surface of a sail made of plastic. However, this configuration has disadvantages that it is not clear how a solar power generation cell is mounted on the surface of the plastic sail ,and it is difficult to apply this configuration in practice.